MRI

Open Skies MRI can perform all types of exams with the exception of Breast MRI.

What is Magnetic Resonance Imaging (MRI)?

MRI is considered the gold standard in diagnostic imaging in many cases and is continually advancing, as are most other modalities. Like CT, MRI images are thin “slices” of the body but unlike CT, it can image in any plane. It is excellent for imaging soft tissues, ie: muscles, tendons, ligaments, nerves, brain tissue, internal organs and also for detecting infections, spinal cord injuries and characterizing tumors. Depending on the area and the reason for the requested MRI, it may be necessary to inject a contrast dye so the tissues show up more clearly. This dye is completely different than dye used in other studies. Reactions to MRI dye are extremely rare.

MRI uses a very strong magnetic field, up to 50 000 times stronger than the earth’s magnetic field, and radiofrequency waves to acquire images. Our bodies are made up of more than 90% water, which is Hydrogen and Oxygen. Hydrogen is magnetic and the abundance of it makes it the best element for MRI.

When we are not in a strong magnetic field, the Hydrogen protons are randomly moving about. When we are subjected to a strong magnetic field they begin to align with the field. A radiofrequency wave with the same resonant frequency as the precessing Hydrogen protons is then sent into the area being scanned and knocks the protons off of their axis. When the wave is stopped, the protons relax back to align with the magnetic field and as they’re relaxing back, they give off a signal. This signal is collected by a coil, which is surrounding the anatomy of interest, and then transformed into an image. This is the basis of how MRI works.

Technical

Our MRI machine is the Philips Panorama HFO. Our HFO is the only truly open high field scanner in Canada. It uses a vertical magnetic field rather than horizontal as in a conventional MRI. The HFO also uses solenoid coils which surround the anatomy rather than surface coils in a conventional MRI, which are positioned adjacent to the anatomy. One of the greatest strengths of the HFO is in Musculoskeletal imaging. In order to achieve good image quality with MRI, the anatomy must be positioned in the center of the magnetic field, where the field is most homogeneous. This is called isocenter. The HFO table not only moves in and out of the scanner but also side to side which allows for isocentric imaging for all anatomy. The ability to image at isocenter in conjunction with the use of solenoid coils, results in superb image quality.

Because the HFO is open on the sides it is also more accommodating for Bariatric and Claustrophobic patients. This also allows for a multitude of positioning possibilities which would not be possible with a conventional scanner.